Self-locking-and-measuring ruler for computer-printout forms

Abstract

The present invention provides a self-locking-and-measuring, straight-edge apparatus designed to allow one to very accurately draw spaced parallel lines, particulary horizontal ones, the straight-edge being especially designed for ruling computer-printout forms. The apparatus comprises a scaled guide bar that is affixed perpendicularly to a drafting table, or the like, on which a straight-edge assembly is slidably and adjustably mounted, so as to move longitudinally along the scaled guide bar. The straight-edge assembly includes a base plate having a spring-biased latch positioned to selectively engage any one of a plurality of scaled notches formed along the longitudinal edges of the scaled guide bar. A straight edge is adjustably attached to the base plate.

I claim: 
     
       1. A self-locking-and-measuring, straight-edge apparatus, comprising: a scaled guide-bar member adapted to be fixedly secured to a substantially flat-surfaced structure;   a plurality of notches formed along at least one longitudinal edge of said scaled guide-bar member;   a scale having predetermined measures disposed on said scaled guide-bar member, whereby said notches are spaced apart with respect to said scale;   a groove formed longitudinally in said scaled guide-bar member and parallel with said notched edge thereof;   a base-plate member adapted to be slidably mounted to said scaled guide-bar member;   wherein said base-plate member includes means for adjusting the angular position of said straight edge with respect to said scaled guide-bar members;   guide means mounted to said base-plate member and adapted to be slidably received in said longitudinal groove for perpendicular movement along said scaled guide-bar member;   wherein said guide means comprises a pair of aligned guide pins mounted and located in said base plate member, whereby said guide pins are slidably received in said longitudinal groove of said scaled guide-bar member;   latching means operably attached to said base-plate member for selective engagement with said notches;   wherein said latching means comprises:   a latching tongue adapted to engage selective notches along said edge of said scaled guide-bar member, said latching tongue being slidably attached to said base plate;   a spring positioned to engage said latching tongue in biased engagement with said notches; and   a release knob secured to said latching tongue; and   a straight edge secured to said base-plate member so as to be positioned normal to said scaled guide-bar member, whereby lines may be drawn horizontal to the scaled guide-bar member.   
     
     
       2. The apparatus as recited in claim 1, wherein said straight-edge-adjusting means comprises: a pivot means securing one end of said straight edge to said base plate member, whereby said straight edge is pivotable from a horizontal position to a selected angular position; and   a locking means connected between said base plate member and said straight edge, whereby said straight edge is adapted to be selectively positioned relative to said scaled guide-bar member.   
     
     
       3. The apparatus as recited in claim 2, wherein said locking means comprises: a threaded pin mounted in said straight edge;   an arcuate slot formed in said base plate member through which said threaded pin passes; and   a finger nut threadably mounted to said threaded pin, whereby said finger nut is tightened against said base plate member so as to lock said straight edge in a selective position.   
     
     
       4. The apparatus as recited in claim 3, wherein said latching means includes a groove formed in the bottom surface of said base plate member and adapted to slidably receive said latching tongue therein. 
     
     
       5. The apparatus as recited in claim 2, said scaled guide bar is formed having first and second longitudinal edges, both of said longitudinal edges including a plurality of said notches, wherein said notches of said first longitudinal edge are spaced apart according to said scale adjacently disposed thereto, and wherein said notches of said second longitudinal edge are spaced apart according to said scale adjacently disposed thereto, whereby said oppositely disposed notches are provided with separately arranged scales.